-al a-a a-b a-t aaa aab aad aal aar aat ab- aba abb abd abl abr abt ad- ada adb add adl adr adt al- ala alb ald all alr alt ar- ara arb ard arl arr art at- ata atb atd atl atr att baa bab bad bal bar bat bba bbb bbd bbl bbr bbt bda bdb bdd bdl bdr bdt bla blb bld bll blr blt bra brb brd brl brr brt bta btb btd btl btr btt daa dab dad dal dar dat dba dbb dbd dbl dbr dbt dda ddb ddd ddl ddr ddt dl- dla dlb dld dll dlr dlt dra drb drd drl drr drt dta dtb dtd dtl dtr dtt la- laa lab lad lal lar lat lba lbb lbd lbl lbr lbt lda ldb ldd ldl ldr ldt lla llb lld lll llr llt lra lrb lrd lrr lrt lta ltb ltd ltl ltr ltt ra- raa rab rad ral rar rat rba rbb rbd rbl rbr rbt rda rdb rdd rdl rdr rdt rla rld rll rlr rlt rra rrb rrd rrl rrr rrt rta rtb rtd rtl rtr rtt taa tab tad tal tar tat tba tbb tbd tbl tbr tbt tda tdb tdd tdl tdr tdt tla tld tll tlr tlt tra trb trd trl trr trt tta ttb ttd ttl ttr ttt